Control Valve Pulse Timing for Vibration-Safe Drive Motion
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Solution Overview
Problem
Mechanical systems with movably mounted bodies driven by medium-operated drive units often experience undesirable vibrations due to inertia and damping characteristics, particularly when the switching frequency of control valves aligns with the system's eigenfrequency, leading to high vibration amplitudes.
Innovation Solution
A method involving a control valve actuated by a control signal with two switching pulses of equal pulse duration, where the time interval between the pulses is adapted to the intrinsic period duration of the mechanical system, effectively suppressing or reducing ringing and enhancing system dynamics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the switching frequency of the control valve is increased to improve response speed, then the drive movement control is improved, but undesirable vibrations are excited when the switching frequency aligns with the eigenfrequency of the mechanical system
Solution Approach 1:
The control signal uses periodic switching pulses with a time interval adapted to the intrinsic period duration of the mechanical system. By making the control action periodic and synchronizing it with the system's natural oscillation period, the control achieves effective response while avoiding resonance excitation that would cause harmful vibrations.
Solution Approach 2:
The invention changes the temporal parameters of the control signal, specifically adapting the time interval between switching pulses to match the intrinsic period duration of the mechanical system. This parameter adaptation allows the system to operate at high switching frequencies for fast response while avoiding the eigenfrequency that would excite harmful vibrations.
2Productivity
If the time interval between switching pulses is reduced to increase switching frequency, then productivity is improved, but vibration amplitudes increase when excitation occurs at eigenfrequency
Solution Approach 1:
The control signal employs periodic switching pulses where the time interval is specifically adapted to the intrinsic period duration of the mechanical system. This periodic control approach enables high switching frequency for improved productivity while the synchronization with the system's natural period prevents resonance and keeps vibration amplitudes low.
Solution Approach 2:
The invention makes the control system dynamic by adapting the time interval between switching pulses to the intrinsic period duration of the mechanical system. This dynamic parameter adjustment allows the system to achieve high productivity through increased switching frequency while automatically avoiding conditions that would cause excessive vibrations.
3Object-affected harmful factors
If the mechanical system design is modified to reduce vibration tendency, then harmful vibrations are reduced, but device complexity increases due to additional design constraints
Solution Approach 1:
The invention replaces mechanical design modifications with a control-based solution. Instead of changing the mechanical structure to reduce vibration tendency, the patent uses a control signal with adapted time intervals to avoid exciting vibrations. This substitution keeps the mechanical design simple while achieving vibration reduction through intelligent control.
Solution Approach 2:
The control system automatically adapts the time interval between switching pulses to the intrinsic period duration of the mechanical system. This self-adjusting control approach reduces vibrations without requiring complex mechanical design modifications, allowing the system to manage its own vibration characteristics through intelligent control parameter selection.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces undesirable vibrations and increases the dynamics of the mechanical system by aligning the control signal pulses with the system's natural frequency, minimizing vibration amplitudes and improving movement control.
Implementation Method 1
a drive unit which can be operated with a medium for driving the movably mounted body
Implementation Method 2
Such vibrations can be attributed to, among other things, the inertia and/or the damping characteristics of the mechanical system
Implementation Method 3
Such vibrations can be attributed to, among other things, the inertia and/or the damping characteristics of the mechanical system
Implementation Method 4
When the switching frequency of a control valve lies in the vicinity of a eigenfrequency of the mechanical system, particularly high vibration amplitudes can occur during the excitation of such undesirable vibrations
Data Source
AI summary
A method for controlling movement of a movably mounted body (14) of a mechanical system (2, 56, 62). The mechanical system (2, 6, 62) includes a drive unit (4, 64), which is operated by a medium, and also a control valve (20, 22). The movably mounted body (14) is driven by the drive unit (4, 64). A drive movement of the drive unit (4, 64) is controlled with the aid of the control valve (20, 22). In order to avoid or reduce excitation of undesired vibrations in the mechanical system (2, 56, 62), it is proposed that the control valve (20, 22) be actuated using a control signal (u(t)) which comprises a first and also a further switching pulse (S1, S3) each having a prespecified pulse duration. The pulse duration of the first switching pulse (S1) is equal to the pulse duration of the further switching pulse (S3). A time difference (Δt1-3) between the start of the first pulse (S1) and the start of the further switching pulse (S3) is matched to a natural period duration of the mechanical system (2, 56, 62).